To learn how to get image from url, we create a simple example.
Step 1: create new android project.
Step 2: file AndroidManifest.xml
add:
<uses-permission android:name="android.permission.INTERNET" />
Step 3: create the main layout: res\layout\activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.tutorialspots.getimage.MainActivity">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TUTORIALSPOTS.COM"
android:textColor="#FF0000"
android:textSize="30dp"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:id="@+id/textView" />
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/imageView"
android:layout_below="@+id/textView"
android:layout_centerHorizontal="true" />
</RelativeLayout>
Step 4: create new class ImageViewHelper.java
package com.tutorialspots.getimage;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.util.Log;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
/**
* Created by Tutorialspots on 1/10/2016.
*/
public class ImageViewHelper {
public static Bitmap getBitmapFromURL(String src) {
try {
URL url = new URL(src);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
// Sets the flag indicating whether this URLConnection allows input.
connection.setDoInput(true);
connection.connect();
InputStream inputStream = connection.getInputStream();
Bitmap bitmap = BitmapFactory.decodeStream(inputStream);
return bitmap;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
}
Step 5: file MainActivity.java
Method 1:
package com.tutorialspots.getimage;
import android.graphics.Bitmap;
import android.os.StrictMode;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ImageView;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
String url = "http://tutorialspots.com/wp-content/uploads/2013/04/1.png";
ImageView imageView;
Bitmap bitmap;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
imageView = (ImageView) findViewById(R.id.imageView);
bitmap = ImageViewHelper.getBitmapFromURL(url);
if(bitmap == null)
Toast.makeText(getApplicationContext(), "Can't get image from url", Toast.LENGTH_LONG).show();
else
imageView.setImageBitmap(bitmap);
}
}
Note: if you don’t use the code:
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
You will get the error:
01-09 18:27:18.593 20909-20909/com.tutorialspots.getimage W/System.err: android.os.NetworkOnMainThreadException 01-09 18:27:18.593 20909-20909/com.tutorialspots.getimage W/System.err: at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1117) 01-09 18:27:18.593 20909-20909/com.tutorialspots.getimage W/System.err: at java.net.InetAddress.lookupHostByName(InetAddress.java:385) 01-09 18:27:18.593 20909-20909/com.tutorialspots.getimage W/System.err: at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236) 01-09 18:27:18.593 20909-20909/com.tutorialspots.getimage W/System.err: at java.net.InetAddress.getAllByName(InetAddress.java:214) 01-09 18:27:18.593 20909-20909/com.tutorialspots.getimage W/System.err: at libcore.net.http.HttpConnection.<init>(HttpConnection.java:70) 01-09 18:27:18.593 20909-20909/com.tutorialspots.getimage W/System.err: at libcore.net.http.HttpConnection.<init>(HttpConnection.java:50) 01-09 18:27:18.593 20909-20909/com.tutorialspots.getimage W/System.err: at libcore.net.http.HttpConnection$Address.connect(HttpConnection.java:340) 01-09 18:27:18.593 20909-20909/com.tutorialspots.getimage W/System.err: at libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:87) 01-09 18:27:18.593 20909-20909/com.tutorialspots.getimage W/System.err: at libcore.net.http.HttpConnection.connect(HttpConnection.java:128) 01-09 18:27:18.593 20909-20909/com.tutorialspots.getimage W/System.err: at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:316) 01-09 18:27:18.593 20909-20909/com.tutorialspots.getimage W/System.err: at libcore.net.http.HttpEngine.connect(HttpEngine.java:311) 01-09 18:27:18.593 20909-20909/com.tutorialspots.getimage W/System.err: at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:290) 01-09 18:27:18.593 20909-20909/com.tutorialspots.getimage W/System.err: at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:240) 01-09 18:27:18.593 20909-20909/com.tutorialspots.getimage W/System.err: at libcore.net.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:81) 01-09 18:27:18.593 20909-20909/com.tutorialspots.getimage W/System.err: at com.tutorialspots.getimage.ImageViewHelper.getBitmapFromURL(ImageViewHelper.java:21) 01-09 18:27:18.593 20909-20909/com.tutorialspots.getimage W/System.err: at com.tutorialspots.getimage.MainActivity.onCreate(MainActivity.java:20) 01-09 18:27:18.593 20909-20909/com.tutorialspots.getimage W/System.err: at android.app.Activity.performCreate(Activity.java:5104) 01-09 18:27:18.593 20909-20909/com.tutorialspots.getimage W/System.err: at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080) 01-09 18:27:18.593 20909-20909/com.tutorialspots.getimage W/System.err: at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144) 01-09 18:27:18.597 20909-20909/com.tutorialspots.getimage W/System.err: at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230) 01-09 18:27:18.597 20909-20909/com.tutorialspots.getimage W/System.err: at android.app.ActivityThread.access$600(ActivityThread.java:141) 01-09 18:27:18.597 20909-20909/com.tutorialspots.getimage W/System.err: at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234) 01-09 18:27:18.597 20909-20909/com.tutorialspots.getimage W/System.err: at android.os.Handler.dispatchMessage(Handler.java:99) 01-09 18:27:18.597 20909-20909/com.tutorialspots.getimage W/System.err: at android.os.Looper.loop(Looper.java:137) 01-09 18:27:18.597 20909-20909/com.tutorialspots.getimage W/System.err: at android.app.ActivityThread.main(ActivityThread.java:5041) 01-09 18:27:18.597 20909-20909/com.tutorialspots.getimage W/System.err: at java.lang.reflect.Method.invokeNative(Native Method) 01-09 18:27:18.597 20909-20909/com.tutorialspots.getimage W/System.err: at java.lang.reflect.Method.invoke(Method.java:511) 01-09 18:27:18.597 20909-20909/com.tutorialspots.getimage W/System.err: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793) 01-09 18:27:18.597 20909-20909/com.tutorialspots.getimage W/System.err: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560) 01-09 18:27:18.597 20909-20909/com.tutorialspots.getimage W/System.err: at dalvik.system.NativeStart.main(Native Method)
Method 2: use AsyncTask
package com.tutorialspots.getimage;
import android.graphics.Bitmap;
import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ImageView;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
String url = "http://tutorialspots.com/wp-content/uploads/2013/04/1.png";
ImageView imageView;
Bitmap bitmap;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
imageView = (ImageView) findViewById(R.id.imageView);
ImageLoadAsyncTask imageLoadAsyncTask = new ImageLoadAsyncTask();
imageLoadAsyncTask.execute(new String[]{url});
}
public class ImageLoadAsyncTask extends AsyncTask<String, Void, String>{
@Override
protected String doInBackground(String... strings) {
bitmap = ImageViewHelper.getBitmapFromURL(strings[0]);
return null;
}
@Override
protected void onPostExecute(String s) {
if(bitmap == null)
Toast.makeText(getApplicationContext(), "Can't get image from url", Toast.LENGTH_LONG).show();
else
imageView.setImageBitmap(bitmap);
}
}
}
Step 6: run for test:
